Modal Operator Fixes
Thanks again batFINGER

The following works great:

import bpy

class ModalOperator(bpy.types.Operator):
    bl_idname = "object.modal_operator"
    bl_label = "Simple Modal Operator"

    def execute(self, context):
        print("This is the modal operator")
        return {'FINISHED'}

    def modal(self, context, event):
        if event.type == 'ESC':  # Confirm
            print("This is finished")
            return {'FINISHED'}
 # .value == 'PRESS' will trigger the event once. 
 # or do: if event.type == 'P' and if.event.value == 'PRESS':
        elif event.alt:
            if event.type == 'P':
                if.event.value == 'PRESS': # Confirm
                    print("This is a continuous pass through")
            return {'PASS_THROUGH'}

        return {'PASS_THROUGH'}

    def invoke(self, context, event):
        print("This is the invoker")

        context.window_manager.modal_handler_add(self)
        return {'RUNNING_MODAL'}

bpy.utils.register_class(ModalOperator)

bpy.ops.object.modal_operator('INVOKE_DEFAULT')